How to deal with the pollution of reflow soldering process?

Reflow welding transfers heat energy through the laminar movement of hot air. The heater and fan are used to continuously heat up and circulate the air in the furnace. The parts to be welded receive the heating of hot gas in the furnace, so as to realize welding. Reflow soldering has hot spots with uniform heating and stable temperature. The temperature difference between the top and bottom of PCB and the temperature increase along the furnace length are not easy to control and are generally not used alone. With the continuous expansion of SMT application and the progress of components, miniaturization and continuous improvement of reflow soldering, it can more accurately control the temperature distribution of various parts of the furnace and facilitate the ideal adjustment of temperature curve.

The circuit board and components are welded together by reflow soldering process. In the whole SMT production process, there are two links that are prone to pollution. The first link is in the process of printing and pasting. If you directly contact the solder paste or wipe the solder paste casually, it will cause pollution; The second link is that in the reflow soldering process, the circuit board brushed with solder paste and pasted with components enters the reflow soldering path. Second, the soldering production is formed by melting and cooling the solder paste through reflow soldering. There are chemicals that damage the body in the solder paste, which will also produce environmental pollution.

Pollution treatment method of reflow soldering process:

The main components in the solder paste are tin powder and flux. Tin powder affects the performance of the whole solder paste. The difference between tin powder and alloy composition lies in the metal composition. In the commonly used solder paste, the metal composition of tin powder includes 2 to 3 kinds of metals such as tin, lead, silver, copper and bismuth. Both flux and lead are harmful to human body. Therefore, if the reflow soldering is operated improperly, it will cause environmental pollution. Therefore, there should be a recycling system for polluted air in reflow welding. The smoke exhaust and ventilation of reflow welding must be done well. Reflow welding smoke filter should be installed to reduce waste gas pollution.